Energy harvesting methods for providing autonomous electrical power to mobile devices

ABSTRACT

A method is provided that integrates an autonomous energy harvesting capacity in a mobile device in an aesthetically neutral manner. A unique set of structural features combine to implement a hidden energy harvesting system on a surface of the mobile device body structure or casing to provide electrical power to the mobile device, and/or to individually electrically-powered components in the mobile device. Color-matched, image-matched and/or texture-matched optical layers are formed over energy harvesting components, including photovoltaic energy collecting components. Optical layers are tuned to scatter selectable wavelengths of electromagnetic energy back in an incident direction while allowing remaining wavelengths of electromagnetic energy to pass through the layers to the energy collecting components below. The layers appear opaque when observed from a light incident side, while allowing at least 50%, and as much as 80+%, of the energy impinging on the energy or incident side to pass through the layer.

BACKGROUND

This application is a continuation of United States (U.S.) patentapplication Ser. No. 15/416,456, entitled ENERGY HARVESTING METHODS FORPROVIDING AUTONOMOUS ELECTRICAL POWER TO MOBILE DEVICES, filed in theUnited States Patent and Trademark Office (USPTO) on Jan. 26, 2017,which published as US 2018-0212554 A1 on Jul. 26, 2018, and which issuedas U.S. Pat. No. 11,554,576 on Jan. 17, 2023, the entire disclosure ofwhich is hereby incorporated by reference herein in its entirety. Thisapplication is related to U.S. patent application Ser. No. 15/416,384,which was filed on Jan. 26, 2017 and which published as USPTO pre-grantpublication number US2018-0212553 A1 on Jul. 26, 2018, and which issuedas U.S. Pat. No. 10,525,684 on Jan. 07, 2020 entitled “Energy HarvestingSystems For Providing Autonomous Electrical Power To Mobile Devices”,the disclosure of which is hereby incorporated by reference herein inits entirety.

Field of the Disclosed Embodiments

This disclosure is directed to a unique method for forming a set ofstructural features on an outer surface of a mobile device, or a mobiledevice case, the structural features combining to implement anaesthetically neutral, or aesthetically pleasing, energy harvestingsystem that provides autonomous electrical power to a mobile device onwhich the system is installed, and/or to individuallyelectrically-powered components in the mobile device. Color-matched,image-matched and/or texture-matched optical layers, which provide anessentially same appearance from any viewing angle and provide superiorlight transmission across the range of light impingement angles, areformed over energy harvesting components, including photovoltaiccomponents.

Related Art

U.S. patent applications Ser. Nos. 15/006,143 (the 143 application),which published as USPTO pre-grant publication number US2016-0306078 A1on Oct. 20, 2016, entitled “Systems and Methods for Producing Laminates,Layers and Coatings Including Elements for Scattering and PassingSelective Wavelengths of Electromagnetic Energy,” which published fromthe United States Patent and Trademark Office (USPTO) as U.S. PatentPublication No. US 2016-0306078 A1 on Oct. 20, 2016; and applicationSer. No. 15/006,145 (the 145 application), which published as USPTOpre-grant publication number US2016-0306080 A1 on Oct. 20, 2016,entitled “Systems and Methods for Producing Objects IncorporatingSelective Electromagnetic Energy Scattering Layers, Laminates andCoatings,” which published from the USPTO as U.S. Patent Publication No.US 2016-0306080 A1 on Oct. 20, 2016, and which issued as U.S. Pat. No.10,795,062 on Oct. 6, 2020, each of which was filed on Jan. 26, 2016 andthe disclosures of which are hereby incorporated by reference herein intheir entirety, describe a structure for forming selectably energytransmissive layers and certain real world use cases in which thoselayers may be particularly advantageously employed.

The 143 and 145 applications note that, in recent years, the fields ofenergy harvesting and ambient energy collection have gainedsignificantly increased interest. Photovoltaic (PV) cell layers andother photocell layers, including thin-film PV-type (TFPV) materiallayers, are advantageously employed on outer surfaces of particularstructures to convert ambient light to electricity.

Significant drawbacks to wider proliferation of photocells used in anumber of potentially beneficial operating or employment scenarios arethat the installations, in many instances, unacceptably adversely affectthe aesthetics of the structure, object or host substrate surface onwhich the PV layers are mounted for use. PV layers typically must begenerally visible, and the visual appearance of the PV layers themselvescannot be significantly altered from the comparatively dark greyscale toblack presentations provided by the facial surfaces without renderingthe layers significantly less efficient, substantially degrading theiroperation. Presence of photocells and PV layers in most installationsis, therefore, easily visually distinguishable, often in an unacceptablydistracting, or appearance degrading, manner. Based on these drawbacksand/or limitations, inclusion of photocell arrays, and evensophisticated TFPV material layers, is often avoided in manyinstallations, or in association with many structures, objects orproducts that may otherwise benefit from the electrical energyharvesting capacity provided by these layers. PV layer installations areoften shunned as unacceptable visual detractors or distractors adverselyaffecting the appearance or ornamental design of the structures, objectsor products.

The last several decades have seen an expansive proliferation in allmanner of self-powered (read “battery-powered”) devices. Developmentalefforts are particularly evident in the introduction andcommercialization of all manner of mobile computing and/or communicatingdevices.

The original mobile computing and/or communicating devices had verylimited capability. Therefore, those devices required only limitedbattery power to sustain them for extended periods of time withoutneeding to be recharged. Additionally, earlier generation mobilecomputing and/or communicating devices were often configured to quicklyenter standby modes to reduce battery consumption for significantperiods of time until the mobile computing and/or communicating deviceswere activated for use. Today, mobile devices running sophisticatedapplications are generally always “ON.”

Today, many mobile computing and/or communicating devices includeapplications and components for, for example, device tracking that areactive substantially all the time that the mobile computing and/orcommunicating devices are on. As such, there is a fairly consistentpower drain on the batteries, which are supporting increased overalltotal loads in all modes of operation, and to power individual devicecomponents, of the mobile computing and/or communicating devices.

Separately, many users increasingly rely on consistent reliability andavailability of their mobile computing and/or communicating devices inevery activity in which they participate. Put another way, the mobilecomputing and/or communicating devices are always on and always in use,thereby causing increased power drain on the batteries. Batterytechnology continues to improve to meet these requirements. The advancesin battery technology, however, to address this power drain as thenumbers and types of applications, and in instances separatelyelectrically-powered components, provided for user convenience in allmanner of mobile devices increases, have tended to lag behind userneeds.

SUMMARY

The 143 and 145 applications introduce systems and methods that provideparticularly formulated energy or light transmissive overlayers, whichmay be provided to “hide” typical photoelectric energy generatingdevices. These overlayers, generally in the form of surface treatmentsand/or coverings, are formulated to support unique energy transmissionand light refraction schemes to effectively “trick” the human eye intoseeing a generally opaque surface when observed from a light incidentside. These overlayers are formulated to support transmission of visuallight, or near-visual light, in a manner that allows a substantialpercentage (at least 50% and up to 80+%) of the electromagnetic energyimpinging on the surface of the overlayer to penetrate the surfacetreatments and coverings in a comparatively unfiltered manner. Theoverlayers also provide an opaque appearing surface that exhibits anessentially same appearance when viewed from any viewing angle, and thatsupport a consistently superior light transmission across a full rangeof light impingement angles. The energy transmissive layers disclosed inthe 143 and 145 applications rely on a particular cooperation betweenrefractive indices of the disclosed micron-sized particles or sphereswith cooperating refractive indices of the matrix materials in whichthose micron-sized particles are suspended for deposition on preparedsurfaces. This coincident requirement between the refractive indices ofthe matrix material and the refractive indices of the suspendedparticles limits deposition of these material suspensions of particleson substrates to techniques in which the deposition of the materials canbe carefully controlled.

U.S. patent Applications Ser. Nos. 15/415,851, entitled “Compositions OfMaterials For Forming Coatings And Layered Structures Including ElementsFor Scattering And Passing Selectively Tunable Wavelengths OfElectromagnetic Energy,” and application Ser. No. 15/415,857, entitled“Methods For Making Compositions Of Materials For Forming Coatings AndLayered Structures Including Elements For Scattering And PassingSelectively Tunable Wavelengths Of Electromagnetic Energy,” andapplication Ser. No. 15/415,864, entitled “Delivery Systems and MethodsFor Compositions Of Materials For Forming Coatings And LayeredStructures Including Elements For Scattering And Passing SelectivelyTunable Wavelengths Of Electromagnetic Energy,” each of which was filedJan. 25, 2017, and the disclosures of which are hereby incorporated byreference herein in their entirety improve upon the inventive conceptsdisclosed in the 143 and 145 applications by controlling the refractiveindices of the particles themselves to capture all of the physicalparameters leading to independent color selection in the particles,thereby easing reliance on a cooperative synergy between a compositionof the particles and a composition of the binder or matrix material inwhich the particles are suspended.

It would be advantageous to apply the selectively colorable and/ortexturizable overlayers disclosed in detail in the above applications toenergy harvesting systems associated with mobile devices (which will beused throughout the balance of this disclosure to refer to a broad classof mobile and handheld computing, communicating, and/or sensor-includeddevices), and/or to cases for the mobile devices, to (1) generallyextend periods of operation of battery-powered mobile devices betweenperiods of recharge, and/or (2) individually power at least some of themyriad electrical components in the mobile devices.

Exemplary embodiments may provide substantially transparent micron-sizedparticles in a cooperating binder matrix to produce materialcompositions for layers in which refractive indices of the constituentelements of the layers are cooperatively controlled to producerepeatable coloration in the layers causing them to appear opaque from alight-incident side, and yet retaining a capacity to transmit at least50%, and as much as 80+%, of the incident electromagnetic energytherethrough to impinge, for example, on photoelectric or photovoltaicenergy harvesters positioned behind the layers.

Exemplary embodiments may form energy transmissive layers overphotovoltaic arrays on mobile devices and mobile device cases, theenergy transmissive layers providing an opaque appearing surface thatexhibits an essentially same appearance when viewed from any viewingangle, and supporting a consistently superior light transmission acrossa full range of light impingement angles.

Exemplary embodiments may provide a TFPV material layer on a substratethat is in a form of a mobile device, and particularly a casing for amobile device. The disclosed TFPV material layers may be adhesivelyconformed to the discrete mobile device outer or case portions and thenhidden by being overcoated with the disclosed energy transmissiveoverlayer material.

Exemplary embodiments may provide electrical circuits that convert theenergy collected by the TFPV layer into usable electrical power for useby the electrical component systems in the mobile devices.

These and other features, and advantages, of the disclosed systems andmethods are described in, or apparent from, the following detaileddescription of various exemplary embodiments.

BRIEF DESCRIPTION OF THE DRAWINGS

Various exemplary embodiments of the disclosed methods for forming aunique set of structural features on an outer surface of a mobile deviceor mobile device casing that combine to implement an aestheticallyneutral, or aesthetically pleasing, energy harvesting system that isconfigured to provide autonomous electrical power to the mobile device,and/or to individually electrically-powered components in the mobiledevice, will be described, in detail, with reference to the followingdrawings, in which:

FIG. 1 illustrates a schematic diagram of an exemplary objectenergy/light scattering surface layer disposed on a structural bodymember substrate according to this disclosure;

FIG. 2 illustrates a schematic diagram of an exemplary mobile deviceenergy harvesting system including a laminated energy harvestingcomponent with, as one or more of the laminate layers, a TFPV materiallayer disposed on a mobile device body or casing, and an energy/lightscattering layer according to this disclosure disposed over the TFPVmaterial layer;

FIGS. 3A-3D illustrate a series of schematic diagrams of steps in anexemplary process for forming a laminated energy harvesting component,with at least one layer constituted as an energy/light scattering layer,according to this disclosure;

FIG. 4 illustrates an exemplary embodiment of a detail of anenergy/light scattering layer usable in the energy harvesting systemsaccording to this disclosure;

FIG. 5 illustrates a schematic diagram of an exemplary mobile devicecasing to provide an example of emplacement of a laminated energyharvesting component according to this disclosure on an outer surface ofthe mobile device casing;

FIG. 6 illustrates a schematic diagram of an exemplary assembly lineusable for automated forming of the exemplary laminated energyharvesting component on a surface of a mobile device casing according tothis disclosure; and

FIG. 7 illustrates a flowchart of an exemplary method for integrating aunique energy harvesting system, including an energy/light scatteringlayer, on a surface of a mobile device casing according to thisdisclosure.

DETAILED DESCRIPTION OF EMBODIMENTS

The disclosed method for forming a unique set of structural features asurface of a mobile device body or casing that combine to implement anaesthetically neutral, or aesthetically pleasing, energy harvestingsystem that is configured to provide autonomous electrical power to amobile device, and/or to individually electrically-powered components inthe mobile device, will be described as being particularly usable forextending a period of operation before the mobile device needs to berecharged. The described real-world applications for the disclosedenergy harvesting systems should not be considered as limiting thosesystems to charging, recharging, powering, or otherwise providingelectrical power to any particular battery, or other electrical systemcomponent, only in any particular type of mobile computing and/orcommunicating device. Rather, the disclosed embodiments are intended toprovide an overview of a particular system that may be implemented toautonomously provide electrical power to virtually any mobile deviceand/or to any individually electrically-powered component in any mobiledevice.

Reference will be made to substantially transparent multi-layermicron-sized particles, and the material compositions in which thoseparticles may be delivered, and the systems and methods for delivery ofthose material compositions onto mobile device body structure, andmobile device casing, surfaces that have been previously provided withconformal photovoltaic arrays, particularly in a form of a TFPV materiallayer, according to this disclosure. The disclosed schemes may includetechniques for depositing and curing material compositions that suspendsubstantially transparent multi-layer micron-sized particles insubstantially transparent binder or matrix materials, techniques fordeveloping material compositions into structural layers, and deliverysystems and techniques for developing the multi-layered structure, whichmay be a laminated structure, in which color-selectable electromagneticenergy transmissive layers are formed over the photovoltaic components.These layers, once formed, may selectively scatter specific wavelengthsof electromagnetic energy impinging on an energy incident side of thelayers, while allowing remaining wavelengths of the electromagneticenergy to pass therethrough. These layers may uniquely implement opticallight scattering techniques in such energy transmissive layers toprovide an aesthetically neutral outer surface that is substantiallycomparable to a conventional painted surface. These layers may alsoprovide an opaque appearing surface that exhibits an essentially sameappearance when viewed from any viewing angle, and that supports aconsistently superior light transmission across a full range of lightimpingement angles. Because the disclosed “coatings” do not includepigment materials, the overlayers comprised of these substantiallytransparent materials are not susceptible to fading over time. In orderto provide a usable electrical energy, the disclosed overlayers may beparticularly formed to selectively scatter particular wavelengths ofelectromagnetic energy, including light energy in the visual,near-visual or non-visual range, while allowing remaining wavelengths topass therethrough with a transmissive efficiency of at least 50%, and asmuch as 80+%, with respect to the impinging energy.

Additional details regarding the above-discussed energy transmissivelayers are available in the various related applications cataloguedabove, the disclosures of which are incorporated by reference herein intheir entireties.

Exemplary embodiments described and depicted in this disclosure shouldnot be interpreted as being specifically limited to any particularlylimiting material composition of the individually-describedsubstantially transparent multi-layer micron-sized particles, and thebinder matrices in which those particles may be suspended, except asindicated according to the material properties generally outlined below.Further, the exemplary embodiments described and depicted in thisdisclosure should not be interpreted as specifically limiting theconfiguration of any of the described layers, or of the particularmobile devices, or mobile device casings, as substrates on which thedisclosed energy harvesting structures may be formed.

References will be made to individual ones, or classes, of energy/lightcollecting sensor components and energy/light activated devices that maybe operationally mounted in, installed in or placed behind the disclosedenergy/light scattering, light directing or light transmissive layers soas to be hidden from view when an object including such sensorcomponents or devices is viewed from a viewing, observation or lightincident outer surface of the object or layer, from which perspectivethe energy/light scattering, light directing or light transmissivelayers may appear “opaque” to the incident electromagnetic energy. Thesereferences are intended to be illustrative only and are not intended tolimit the disclosed concepts, compositions, processes, techniques,methods, systems and devices in any manner. It should be recognized thatany advantageous use of the disclosed structures and schemes forproviding an autonomous energy harvesting capability in a mobile deviceemploying systems, methods, techniques, and processes such as thosediscussed in detail in this disclosure is contemplated as being includedwithin the scope of the disclosed exemplary embodiments.

In this regard, the disclosed systems and methods will be described asbeing particularly adaptable to hiding certain photovoltaic materials,and the emerging class of increasingly efficient TFPV materials ormaterial layers, which are typically mils thick, on the surfaces of, orwithin objects, behind layers that may appear opaque from a viewing,observation or light incident side. As used throughout the balance ofthis disclosure, references to TFPV material layers are not intended toexclude other types of photovoltaic materials, and/or any generallyknown configuration as to any photocells, which may be adapted for usein particular mobile device body structures and casings.

FIG. 1 illustrates a schematic diagram 100 of an exemplary objectenergy/light scattering surface layer 120 disposed on a transparentportion of a body structure 110. As shown in FIG. 1 , the energy/lightscattering layer 120 is configured to allow first determined wavelengthsof energy/light, WLp, to pass through the energy/light scattering layer120. The configuration of the energy/light scattering layer 120simultaneously causes certain second determined wavelengths ofenergy/light, WLs, to be scattered back in an incident directionsubstantially as shown.

The energy/light scattering layer 120 may be configured of substantiallytransparent micron-sized particles of varying sizes. In embodiments,these particles may be substantially in a range of 5 microns or less.The substantially transparent micron-sized particles may be stabilizedin structural or other layers further comprised ofsubstantially-transparent matrix materials including, but not limitedto, dielectric materials. An ability to configure the substantiallytransparent micron-sized particles to “tune” the light scatteringsurface of the light scattering layer 120 to scatter particular seconddetermined wavelengths of energy/light, WLs, may provide the capacity ofthe energy/light scattering layer 120 to produce a desired visualappearance in a single color, multiple colors, or according to animage-wise visual presentation provided by the energy/light scatteringlayer 120. Put another way, depending on a particular composition of thesubstantially transparent micron-sized particles comprising theenergy/light scattering layer 120 (or multiple layers), one or morecolors, textures, color patterns, or color-patterned images may bevisually produced by the energy/light scattering layer 120.

In cases where the incident energy includes wavelengths in the visualspectrum, refractive indices of the energy/light scattering layer 120may be selectively tuned based on structural compositions of thesubstantially transparent micron-sized particles, and thesubstantially-transparent binder or matrix materials in which theparticles are suspended. In embodiments for use in mobile device outerstructures or mobile device cases/casings according to this disclosure,the energy/light scattering layer 120 may be intended to appear as asingle color across a surface of the energy/light scattering layer 120.To this end, the composition of the particles and matrix scheme acrossthe surface of the energy/light scattering layer 120 may besubstantially identical, or homogenous. In embodiments, however, aconstituent composition of the energy/light scattering layer 120 may bevaried across a surface of the mobile device outer structure or mobiledevice casing in order to present a complex image-wise depiction,including multiple colors and/or multiple textures. Refractive indicesof the energy/light scattering layer 120 may be selectively tuned basedon one or more sizes of the particles, one or more material compositionsof the particles, one or more physical compositions of the particles,one or more material compositions of any matrix within which theparticles may be fixed, interstitial openings or voids between theparticles fixed in the matrix, or any combination of the aboveparameters.

A light scattering effect of the energy/light scattering layer 120 maybe produced in response to illumination generally from ambient light ina vicinity of, and/or impinging on, the surface of the energy/lightscattering layer 120. Alternatively, the light scattering effect of theenergy/light scattering layer 120 may be produced in response to directillumination generally produced by some directed light source 130focusing illumination on the light-incident surface of the energy/lightscattering layer 110.

FIG. 2 illustrates a schematic diagram 200 of an exemplary mobile deviceenergy harvesting system including a laminated substrate surface energyharvesting component with, as one or more of the laminate layers, a TFPVmaterial layer disposed on a mobile device body structure or mobiledevice casing, and an energy/light scattering layer according to thisdisclosure disposed over the TFPV material layer. As shown in FIG. 2 ,the ambient energy/light in a vicinity of the energy/light scatteringlayer 220, or the energy/light directed from an energy/light source 230at the energy/light scattering layer 220, may pass through asubstantially clear overlayer 225, which may be in the form of asubstantially clear protective layer. The energy/light scattering layer220 may be configured to operate in a same manner as the energy/lightscattering layer described above with reference to FIG. 1 . At leastfirst wavelengths of energy/light, WLp, may pass through theenergy/light scattering layer 220, while at least the second wavelengthsof energy/light, WLs, may be scattered back in the incident direction inthe manner described above.

The at least first wavelengths of energy/light, WLp, may impinge on aTFPV material layer 215 that may be disposed on, or adhered to, asurface of a mobile device body structure or mobile device casingcomponent substrate 210. The at least first wavelengths of energy/light,WLp, impinging on the TFPV material layer 215 may cause the TFPVmaterial layer 215 to generate electrical energy which may be passed toan electrical energy interface/conditioning circuit 240 to which theTFPV material layer 215 is electrically connected. The electrical energyinterface/conditioning circuit 240 may properly translate or otherwisecondition the generated electrical energy from the TFPV material layer215 to be one or more of (1) stored in a compatible mobile device energystorage device 250, (2) used to directly supplement the mobile deviceelectrical system 260 or (3) provided to directly power one or moremobile device electrically-powered components 270. In embodiments, theelectrical energy generated from the TFPV material layer 215 may bypassthe electrical energy interface/conditioning circuit 240 and be feddirectly to any of the depicted devices or systems according to the“Direct” line in FIG. 2 .

Mobile devices thus equipped may be provided with at least limitedcharging capabilities when there is no grid power available, such as ina natural disaster or other emergency, or in any off-grid situation.This resilience may facilitate a critical communications link in thosesituations. For example, there are a growing number of regions inundeveloped areas of the world with expanding mobile phone service, butlacking commensurate electrical utility services. The disclosed schemessupport proliferation of mobile device communicating capabilities inthese regions.

Also, growing numbers of mobile computing and/or communicating deviceshave batteries or battery packs that are non-removable by the user. Anability to provide trickle charging for the batteries, and/or batterypacks, may extend battery life, and reduce instances that the devicewould have to be taken into a service center for battery or devicereplacement.

FIGS. 3A-3D illustrate a series of schematic diagrams of steps in anexemplary process 300 for forming a laminated energy harvestingcomponent, with at least one layer constituted as a light scatteringconstituent layer, according to this disclosure.

As shown in FIG. 3A, a substrate component 310 may be provided. Thesubstrate component 310 may be, for example, an outer body structure ofa mobile device or a mobile device casing component.

As shown in FIG. 3B, a photovoltaic layer (or component) 315 may bedisposed on the substrate component 310. The photovoltaic layer 315 maycomprise one or more of a photocell, an array of photocells, or a TFPVmaterial layer. Further, the photovoltaic layer 315 may be positioned ona contiguous surface of the substrate component 310, or may be partiallyembedded in a cavity in the surface of the substrate component 310, ormay be completely embedded in a cavity in the surface of the substratecomponent 310 in a manner that an upper surface of the photovoltaiclayer 315 substantially corresponds to an upper surface of the substratecomponent 310. In embodiments, a TFPV material layer may be adhesivelyattached to, or formed on, the substrate component 310. In embodiments,a surface treatment may be applied to portions of the surface of thesubstrate component 310 that are not covered by the photovoltaic layer315. The surface treatment, when applied, is intended to render anoptical reflectance of the portions on which the surface treatment isapplied to be substantially equal to an optical reflectance of the TFPVmaterial layer in order to provide a consistent undersurface forapplication of an energy/light scattering layer.

As shown in FIG. 3C, an energy/light scattering layer 320 may be formedon/over the photovoltaic layer 315 in a manner that first determinedwavelengths of the ambient light in the vicinity of the energy/lightscattering layer 320 may pass through the energy/light scattering layer320, in the manner described above with reference to the embodimentsshown in FIGS. 1 and 2 , while at least second determined wavelengths ofthe ambient light may be scattered back off the energy/light scatteringlayer 320 in the incident direction in the manner described above.

As shown in FIG. 3D, the laminated structure of the energy harvestingcomponent may be finished by covering, or even encapsulating, thelaminated structure in a substantially clear, protective overcoat orouter layer 325. This protective overcoat or outer layer 325 may be in aform of a clear coat finish.

FIG. 4 illustrates an exemplary embodiment of a detail of anenergy/light scattering layer 400 according to this disclosure. Thedisclosed schemes, processes, techniques or methods may produce anenergy/light scattering layer 400 created using substantiallytransparent multi-layer micron-sized particles 420. Those particles maybe in range of diameters of 5 microns or less embedded in asubstantially-transparent dielectric matrix 410. As an example, thesubstantially transparent multi-layer micron-sized particles 420 mayinclude titanium dioxide nanoparticles in a layered form.

In embodiments of the energy/light scattering layers, colorations of thelayered materials may be achieved through combinations of (1) materialcompositions of the particles, (2) material compositions of the binders,(3) nominal particle sizes, (4) nominal particle spacings, and (5)interplay between any or all of those material factors. That “interplay”is important. In other embodiments, the material interplay may becaptured in varying layers of a substantially transparent multi-layermicron-sized particle, thus requiring the only variables to becontrolled as particle size and particle physical composition. Capturingall of the physical parameters in the substantially transparentmulti-layer micron-sized particle substantially eliminates anyrequirement for constituent interplay between the particles and thebinder, essentially rendering the particles binder or matrix materialagnostic. In embodiments including the multi-layer particles, the binderor matrix material is provided simply to hold the particles where theyland. Spacing between the particles is rendered based on a substantiallyclear, neutral outer coating on the substantially transparentmulti-layer micron-sized particles, typically of a substantiallytransparent dielectric material having a comparatively low (less than 2)index of refraction. The employment of multi-layer particles providesincreased latitude in the use of randomized delivery methods, includingspray delivery of an aspirated composition of non-pigment particulatematerial suspended in a comparatively transparent or relatively clearbinder material.

In embodiments with particles comprised of layered constructions, a coresphere may have a diameter to accommodate an optical path length throughthe core of approximately one half wavelength of light for the color ofinterest and may be comprised of 15 or more individual material layerseach having a thickness to accommodate an optical path length throughthe layer of one quarter wavelength of light for the color of interest.For individualized colors from blue to red this layer-on-layerconstruction surrounding the core sphere may result in an overallparticle size of from about 1.9 microns up to 2.6 microns. This range ofoverall particle sizes for the multi-layered construction of thetransparent spheres is comparable to the typical ranges of diameters ofpaint pigment particles. Apparent colors, patterns or images of lightscattering layers may be produced by adjusting refractive indices of theparticles according to a size of the spherical core and the layers ofmaterial deposited on the spherical core of the particles. Such particlecompositions allow for additional degrees of freedom in adjusting thecolor, transmission and scattering, i.e., in “tuning” the energy/lightscattering effects produced by the composition of the energy/lightscattering layer. As mentioned above, an outer layer may be formed of aneutral, transparent, often dielectric material of a thickness selectedto provide a minimum required separation between the “colorant” layersof the substantially transparent multi-layer micron-sized particles toreduce instances of refractive interference thereby causing variation inthe color presentation provided by the light scattering layer.

Dielectric materials from which the core sphere and the dielectricmaterials may be selected may be chosen generally from a groupconsisting of titanium dioxide, silicon carbide, boron nitride, boronarsenite, aluminum nitride, aluminum phosphide, gallium nitride, galliumphosphide, cadmium sulfide, zinc oxide, zinc selenide, zinc sulfide,zinc telluride, cuprous chloride, tin dioxide, barium titanate,strontium titanate, lithium niobate, nickel oxide, and other similarmaterials.

Particle size is related to the wavelength of interest, in the mannerdescribed above, in order to determine the color of the substantiallytransparent multi-layer micron-sized particles. Spacing between theparticles is related to the size in order to reduce interference betweenthe refractions of separate particles. In embodiments, the binder indexof refraction may be the same as an outer layer of the particles inorder that the outer layer does not optically interact with the nextlayer inward. In such an instance, the outer layer may be thicker andparticle-to-particle optical interaction is minimized. Because wherethere is a difference in index of refraction (according to Snell's Law),a reflection occurs. When two reflections are spaced properly, theinteraction of multiple reflections is what provides the color.

The outer layer may be configured to ensure that the colorant producinglayers of the particles are kept separated. In an instance in which thecolorant producing layers touch, no interaction reflection is generated.A result of a configuration of a particle according to this scheme is aparticle that acts in a form of a Bragg Reflector. Multiple weakreflections of a same wavelength reinforce each other resulting in astrong reflection of a particular wavelength based on the particle size,which determines the particle spacing, and the index of refraction alsodetermines the speed of light which in turn describes the opticalwavelength. A number of particles per unit volume of solvent (matrixmaterial) is essentially going to ensure that the particles alwaystouch.

The outer layer will typically be thicker than the underlayers of whichthe substantially transparent multi-layer micron-sized particle iscomprised in order to attempt to ensure that safe separation ismaintained. If the outer layer is controlled to be composed of amaterial that is at a same index of refraction as the binder or matrixmaterial, the outer layer does not optically react in interaction withthe binder or matrix material. The outer layer will be transparent, andmaintain that transparency when immersed in thesubstantially-transparent binder or matrix material having a same indexof refraction as the outer layer of substantially transparentmulti-layer micron-sized particles. In this manner, the outermostlayers, in their composition and thickness, provide the essentialinterstitial spacing between the colorant components so as to assurecolor fidelity. The layers thus formed will yield only the color that is“built in” to the substantially transparent multi- layer micron-sizedparticles according to the structure of the color yielding/generatingunderlayers inward of the outermost layers in the manner describedbelow.

With enough layers, in a range of 10 to 15, to as many as 30, layers,color concentration would be high enough in each of the particles so asto not require external coloration reinforcement provided by adjacentmulti-layer particles. The outer layers are comparatively clear, as isthe binder or matrix solution, and preferably having a comparativelysame index of refraction as between the material forming the outerlayers and the material forming the binder solution. This is to ensurethat there is no interaction between the particles in the binder, and nointeraction between the particles, specifically the coloryielding/generating components of the particles over a longer distance.The outer layers may be comparatively, e.g., 10 times the thickness ofeach of the underlying dielectric layers.

The substantially transparent multi-layer micron-sized particles may beformed in a very tightly-controlled particle build process. A sphericalcore may be formed in a material or layer deposition process such as,for example, an atomic layer deposition (ALD) process, to achieve thesubstantially transparent multi-layer micron-sized particles accordingto the disclosed schemes. Particle deposition control systems exist thatcan be scaled to produce these substantially transparent multi-layermicron-sized particles. Quality control in the particle build processproduces the necessary level of color consistency. There are, however,deposition processes that can be controlled to the units of nanometersthicknesses.

Additionally, embodiments of the multi-layered particles may includemetallic layers sandwiched in between pairs of dielectric layers. Athickness of the metallic layers may be between 0.01 nm and 10 nm, aslong as the metallic layers remain substantially transparent. Thepresence of such metallic layers is intended to enhance reflectivityproperties with respect to the multi-layered structure of the coloryielding/generating layers of the substantially transparent multi-layermicron-sized particles. Indium titanium oxide (ITO) is an example of ametallic layer that is conductive, yet substantially transparent. Atypical touch screen on a cellular telephone, for example, includes anITO surface.

Any suitable acrylic, polyurethane, clearcoat, or like composed binderor matrix material having a low index of refraction may be adapted tosuspend the multi-layer micron-sized particles for application to abroad spectrum of substrate materials. These may include, but not belimited to, for example, synthetic or natural resins such as alkyds,acrylics, vinyl-acrylics, vinyl acetate/ethylene (VAE), polyurethanes,polyesters, melamine resins, epoxy, silanes or siloxanes or oils. It isenvisioned that, in the same manner that paint pigment particles aresuspended in solution, the substantially transparent multi-layermicron-sized particles according to this disclosure may be suspended insolution as well. Unlike paint pigment particles, however, the opticalresponse of particles according to the disclosed schemes will not “fade”over time because there is no pigment breakdown based on exposure to,for example, ultraviolet (UV) radiation. The disclosed particles mayalso be substantially insensitive to heat.

According to the above, application methodologies that are supportablewith particles according to the disclosed schemes include all of thoseapplication methodologies that are available for application of paints,inks and other coloration substances to substrates. These include thatthe particles suspended solutions can be brushed on, rolled on, sprayedon and the like. Separately, the particles may be pre-suspended in thesolutions for on-site apparatus mixing into the deliverable solutions atthe point of delivery to a substrate surface. The particles may bedelivered via conventional aspirated spray systems and/or via aerosolpropellants including being premixed with the propellants forconventional “spray can” delivery. Finally, the particles may be drydelivered to a binder-coated substrate. Conventional curing methods maybe employed to fix the binder-suspended particles on the varioussubstrates.

In the above-described manner, a finished and stabilized apparentcolored, multi-component colored, texturized or otherwiseimage-developed surface transparent light scattering layer is produced.Mass production of such layers could be according to known delivery,deposition and development methods for depositing the light scatteringlayer forming components on the base structures as layer receivingsubstrates, and automatically controlling the exposure, activationand/or stabilization of the surface components to achieve a particularcolored, multi-colored, texturized and/or image-wise patterned lightscattering layer surface.

Additives may be included in the binder or matrix materials in which thesubstantially transparent multi-layer micron-sized particles are, or areto be, suspended to enhance one or more of a capacity for adherence ofthe formed transmissive layer to a particular substrate, including anadhesive or the like, and a capacity for enhanced curing of the layer,including a photo initiator or the like.

FIG. 5 illustrates a schematic diagram of an exemplary mobile device 500to provide an example of emplacement of a laminated energy harvestingcomponent according to this disclosure on an outer surface of the bodystructure of the mobile device or on a casing for the mobile device. Asshown in FIG. 5 , a principal substrate surface 510 of a structural bodyor casing component of a mobile device 500 may be used to host thelaminated energy harvesting component 520. The substrate surface 510 ofthe structural body or casing component of the mobile device 500 may bepartially or substantially completely covered with the laminatedstructure according to, for example, FIGS. 2 and 3 above. Regardless ofthe placement, wired or wireless connection may be provided to, forexample, an energy conversion component within (for example on aprocessor motherboard) the mobile device in order to collect theelectrical energy generated by the photovoltaic layers in the laminatedstructure and to communicate compatible and/or conditioned electricalenergy to the mobile device system or system components as describedgenerally above in reference to FIG. 2 .

FIG. 6 illustrates a schematic diagram of an exemplary assembly lineusable for automated forming of the exemplary laminated energyharvesting component on an outer surface of a mobile device bodystructure or casing according to this disclosure. The exemplary system600 may be used to prepare and build the laminated energy harvestingcomponent structure in a manner similar to that described above withreference to FIGS. 3A-3D.

As shown in FIG. 6 , the exemplary system 600 may include an assemblyline type transport component 640 which may be in a form of poweredroller elements 642, 644 about which a movable platform in a form of,for example, a conveyor belt 646 may be provided to move a mobile devicebody structure or casing past multiple processing station 680, 682, 684,686 in a direction A to accomplish the layer forming and finishingelements of the laminated energy harvesting component build process.Operation of the transport component may be controlled by a controller660.

A photovoltaic array or TFPV attachment station 610 may be providedalong the assembly line, or separately, to provide for adhesiveadherence of, for example, a TFPV material layer on a surface of themobile device body structure or casing when the mobile device bodystructure or casing is positioned at processing station 680. Operationof the TFPV attachment station 610 may be controlled by the controller660.

A layer forming device 630 may be provided at, for example, processingstation 682 as the mobile device body structure or casing moves indirection A from processing station 680. The layer forming device 630may comprise a plurality of spray nozzles or spray heads 636, 638, whichmay be usable to facilitate deposition of a layer forming material overthe previously placed TFPV material layer on a surface of the mobiledevice body structure or casing.

The layer forming device 630 may be connected to an air source 615 viapiping 617 and may separately be connected to a layer material reservoir620 via piping 622. The layer forming device 630 may be usable to obtaina flow of layer material from the layer material reservoir 620 andentrain that layer material in an airstream provided by the air source615 in a manner that causes aspirated layer material to be ejected fromthe spray nozzles or spray heads 636, 638 in a direction of a surface ofthe mobile device body structure or casing when the mobile device bodystructure or casing is positioned at processing station 682.

The layer material reservoir 620 may include separate chambers for asupply of substantially transparent micron-sized particles and for asupply of binder or matrix material. In embodiments, the particles andthe matrix material may come premixed, the particles and matrix materialmay be mixed in the layer material reservoir 620, or the particles andmatrix material may be separately fed to the layer forming device 630and mixed therein before being entrained in the airstream provided tothe layer forming device 630 by the air source 615. The layer formingdevice 630 may be a mounting structure or, in embodiments, the layerforming device 630 may be a movable structure mounted to the end of, forexample, an articulated arm 634 that is mounted to a base component 632.In embodiments, a particle and matrix material mixture may be providedin a material supply reservoir of a conventional spray gun with an airsource for delivery of the layer material in a delivery operationsimilar to a conventional spray painting of a surface. In embodiments,an entire surface of the mobile device body structure or casing may becovered with the light scattering layer material, not just the portionsof the mobile device body structure or casing covered in the TFPVmaterial layers. In this manner, a consistency of coloration in themobile device body structure or casing finish may be obtained as betweenareas including photovoltaic arrays and areas of the surface of themobile device body structure or casing that do not include suchunderlying elements. Operation of the components of the layer formingdevice 630 (including the articulated arm 634 and the base component632), the air source 615, and/or the layer material reservoir 620, maybe separately controlled by the controller 660.

The mobile device body structure or casing may be translated then to aprocessing position 684 opposite a layer curing station 650 that mayemploy known layer fixing methods including using heat, pressure,photo-initiated chemical reactions and the like to cure and/or finishthe light scattering layers on the surface of the mobile device bodystructure or casing. The mobile device body structure or casing may thenbe translated to a processing station 686 opposite a surface finishingstation 670 which may, for example, to deposit a clearcoat over anentire surface of the mobile device body structure or casing, orundertake other finishing processing of the surface of the mobile devicebody structure or casing.

The exemplary system 600 may operate under the control of a processor orcontroller 660. Layer and object forming information may be inputregarding at least one light scattering layer to be formed and fixed onan object or substrate by the exemplary system 600. The controller 660may be provided with object forming data that is devolved, or parsed,into component data to execute a controllable process in which one ormore light scattering layers are formed to produce a single color, amulti-color, texturized surface or an image-patterned presentation whenviewed from the viewing, observation or light incident side of afinished light scattering layer on the mobile device body structure orcasing.

The disclosed embodiments may include an exemplary method forintegrating a unique energy harvesting system, including an energy/lightscattering layer (energy transmissive layer), on a mobile device bodystructure or casing. FIG. 7 illustrates a flowchart of such an exemplarymethod. As shown in FIG. 7 , operation of the method commences at StepS700 and proceeds to Step S710.

In Step S710, one or more discrete substrate surfaces of a mobile devicebody structure or casing may be prepared to receive a layer of TFPVmaterial. Operation of the method proceeds to Step S720.

In Step S720, a layer of TFPV material may be applied to the preparedsubstrate surface of the mobile device body structure or casingaccording to an application method that may adhere the layer of TFPVmaterial to the mobile device body structure or casing. Compatibleadhesive materials, including chemical, heat, or light activatedadhesive materials, may be used to provide the adherence of the TFPVmaterial layer to the mobile device body structure or casing. It shouldbe noted that portions of the mobile device body structure or casing notcovered by the TFPV material may be separately or coincidentallyprepared with finishes that are comparable to the finish displayed bythe TFPV material layer in order that the mobile device body structureor casing may provide a consistent underlying appearance, particularlywith regard to an optical reflectance, for application of the energytransmissive layer materials thereon. Operation of the method proceedsto Step S730.

In Step S730, a liquefied mixture of components for forming an energytransmissive layer composed of substantially transparent particlessuspended in a substantially transparent liquefied matrix may bedeposited over the layer of TFPV material, or over an entire surface ofa mobile device body structure or casing. Such deposition may beaccording to any technique by which a liquefied matrix, which may appearin the form of the paint-like substance, may be applied to anysubstrate. In this regard, the liquefied mixture may be poured on,rolled on, brushed on, or sprayed on the surface of the mobile devicebody structure or casing. In this latter case, an airstream may beprovided from an air source in which the liquefied mixture may beentrained as one of an aspirated and aerosol liquefied mixture.Operation of the method proceeds to Step S740.

As indicated above, in embodiments, the liquefied mixture may includeformed multi-layered substantially transparent particles suspended in asubstantially transparent liquefied matrix material to form theliquefied mixture. The substantially transparent liquefied matrixmaterial may be selected to have an index of refraction similar to thesubstantially clear outer layers or shells of the substantiallytransparent particles in order to substantially reduce any potential forrefractive interference between adjacent particles when deposited on thesurface of the mobile device body structure or casing. The substantiallytransparent liquefied matrix material may include components to aid inadherence of the finished energy transmissive layers on the portions ofthe surface of the mobile device body structure or casing on which thoselayers are ultimately formed. The substantially transparent liquefiedmatrix material may include components to aid in fixing of thesubstantially transparent particles in the layer, includingheat-activated and/or light-activated hardeners. The sizing of theparticles to be less than 5 microns expands the latitude by which thesubstantially transparent particles suspended in the matrix material maybe delivered to the surface of the mobile device body structure orcasing by rendering those particles compatible with the spray techniquesdiscussed above. As such, in a delivery process that mirrorsconventional spray painting, the aspirated liquefied mixture may bedeposited on the prepared surface to form the energy transmissive layerthat passes certain wavelengths of energy/light through the layer andscatters other selectable wavelengths of energy/light to render aperceptibly single color, multi-color, patterned, texturized orimage-wise presentation of scattered light from the light incidentsurface based on one or more delivery passes for depositing the energytransmissive layer materials according to the above-described schemes.

In Step S740, the deposited liquefied mixture may be developed, cured,or otherwise fixed over the TFPV material layer, and on any otherportions of the overall surface of the mobile device body structure orcasing onto which the liquefied mixture is deposited for coloration ofthose portions of the mobile device body structure or casing to form afixed energy transmissive layer thereon. Operation of the methodproceeds to Step S750.

In Step S750, a protective coating may be applied over the energytransmissive layer. The protective coating may take a form of, forexample, a commercial clearcoat finishing composition. Operation of themethod proceeds to Step S760.

In Step S760, the applied protective coating may be cured or otherwisefixed over the energy transmissive layer formed on the surface of themobile device body structure or casing. Operation of the method proceedsto Step S770.

In Step S770, in instances in which the mobile device casing is aseparate component of the overall mobile device body structure, thefinished mobile device casing may be assembled to the mobile device bodystructure. Operation of the method proceeds to Step S780.

In Step S780, wired (or wireless) connections may be made from anelectrical output of the layer of TFPV material to a compatible and/orconditioning circuit that is configured to provide a connection of theenergy harvesting component in the form of the layered structureincluding the TFPV material layer to one or more of anelectrically-powered component in a mobile device, an electrical powersource in the mobile device and/or an electrical power storage device inthe mobile device. Operation of the method proceeds to Step S790.

In Step S790, the mobile device may be transported for further finishprocessing according to known methods. Operation of the method proceedsto Step S800, where operation of the method ceases.

The above-described exemplary particle and material formulations,layered component build processes, and systems and methods for applyinglaminated energy harvesting components to portions of a mobile devicebody structure or casing reference certain conventional components,energy harvesting elements, materials, and real-world use cases toprovide a brief, general description of suitable operating, productprocessing, energy/light scattering (transmissive) layer forming andmobile device body structure or casing modification and integrationenvironments in which the subject matter of this disclosure may beimplemented for familiarity and ease of understanding. Although notrequired, embodiments of the disclosure may be provided, at least inpart, in a form of hardware control circuits, firmware, or softwarecomputer-executable instructions to control or carry out the laminatedstructure development functions described above. These may includeindividual program modules executed by processors.

Those skilled in the optics, electrical generation and mobile deviceproduction arts will appreciate that other embodiments of the disclosedsubject matter may be practiced in many disparate film forming, layerforming, laminate layer forming and mobile device production systems,techniques, processes and/or devices, including various machining,molding, additive and subtractive layer forming and manufacturingmethods, of many different configurations.

Embodiments within the scope of this disclosure may include processorcomponents that may implement certain of the steps described above viacomputer-readable media having stored computer-executable instructionsor data structures recorded thereon that can be accessed, read andexecuted by one or more processors for controlling the disclosedenergy/light scattering layer forming and mobile device integrationschemes. Such computer-readable media can be any available media thatcan be accessed by a processor, general purpose or special purposecomputer. By way of example, and not limitation, such computer-readablemedia can comprise RAM, ROM, EEPROM, CD-ROM, flash drives, data memorycards or other analog or digital data storage device that can be used tocarry or store desired program elements or steps in the form ofaccessible computer-executable instructions or data structures forcarrying into effect, for example, computer-aided design (CAD) orcomputer-aided manufacturing (CAM) of particular objects, objectstructures, layers, and/or layer components.

Computer-executable instructions include, for example, non-transitoryinstructions and data that can be executed and accessed respectively tocause a processor to perform certain of the above-specified functions,individually or in various combinations. Computer-executableinstructions may also include program modules that are remotely storedfor access and execution by a processor.

The exemplary depicted sequence of method steps represent one example ofa corresponding sequence of acts for implementing the functionsdescribed in the steps of the above-outlined exemplary method. Theexemplary depicted steps may be executed in any reasonable order tocarry into effect the objectives of the disclosed embodiments. Noparticular order to the disclosed steps of the methods is necessarilyimplied by the depiction in FIG. 7 , except where a particular methodstep is a necessary precondition to execution of any other method step.

Although the above description may contain specific details, they shouldnot be construed as limiting the claims in any way. Other configurationsof the described embodiments of the disclosed systems and methods arepart of the scope of this disclosure.

It will be appreciated that various of the above-disclosed and otherfeatures and functions, or alternatives thereof, may be desirablycombined into many other different systems or applications. Also,various alternatives, modifications, variations or improvements thereinmay be subsequently made by those skilled in the art which are alsointended to be encompassed by the following claims.

We claim:
 1. A method for integrating an energy harvesting system in amobile device, comprising: arranging an energy harvesting element on asurface of one of a mobile device body structure or casing; andarranging an energy transmissive layer arranged over the energyharvesting element on the surface of the one of the mobile device bodystructure or casing, the energy transmissive layer having a body-facingside facing the surface of the one of the mobile device body structureor casing, and an energy-incident side opposite the body-facing side,forming the energy transmissive layer of a material compositioncomprising a plurality of substantially-transparent particles and asubstantially-transparent matrix material that fixes the plurality ofsubstantially-transparent particles in a layer arrangement, wherein thesubstantially-transparent particles are fixed in thesubstantially-transparent matrix material in a manner that causes theenergy-incident side to reflect substantially all of one or moreselectable wavelengths of the impinging light energy in all directionson the energy-incident side to present a consistent opaque appearance atsaid one or more selectable wavelengths when viewed from substantiallyany aspect, forming each of the substantially-transparent particles tocomprise a spherical core formed of a first transparent dielectricmaterial, the spherical core having a value of a physical diameter equalto a half wavelength of a first selected color of light component to bereflected by the particle modified by a refractive index of the firsttransparent dielectric material; a plurality of material layers disposedradially outwardly from the spherical core, each of the plurality ofmaterial layers being formed of at least a second transparent dielectricmaterial, and having a value of a physical thickness equal to a quarterwavelength of at least a second selected color of light component to bereflected by the particle modified by a refractive index of the at leastthe second transparent dielectric material; and an outer coatingcomprised of another transparent dielectric material having a selectedindex of refraction of 2 or less, the outer coating having a thicknessthat substantially eliminates reflective interference between the colorsreflected by adjacent particles when in contact with one another.
 2. Themethod of claim 1, the energy transmissive layer passing 50% or more ofthe light energy impinging on the energy transmissive layer through theenergy transmissive later to activate the energy harvesting element. 3.The method of claim 1, the energy harvesting element comprising aphotovoltaic element.
 4. The method of claim 3, the photovoltaic elementbeing a photovoltaic film (PVF) material.
 5. The method of claim 4,further comprising applying the PVF material to one or more firstdiscrete portions of the surface of the one of the mobile device bodystructure or casing.
 6. The method of claim 5, further comprisingapplying a layer of adhesive to the one or more first discrete portionsof the surface of the one of the mobile device body structure or casingbefore applying the PVF material to the one or more first discreteportions, the layer of adhesive affixing the PVF material to the surfaceof the one of the mobile device body structure or casing in the one ormore first discrete portions.
 7. The method of claim 5, furthercomprising applying a surface treatment to at least second portions ofthe surface of the one of the mobile device body structure or casing,the second portions of the surface of the one of the mobile device bodystructure or casing being different portions than the first portions,and the surface treatment rendering an optical reflectance of the secondportions substantially equal to an optical reflectance of the PVFmaterial in the first portions.
 8. The method of claim 1, furthercomprising establishing an electrical connection from the energyharvesting element to at least one of an electrical energy power source,an electrical energy storage device and an electrically poweredcomponent device in the mobile device for transmitting electrical energygenerated by the electrical harvesting element.
 9. The method of claim8, the electrical connection comprising at least one of an electricalenergy converting circuit or an electrical energy conditioning circuit.10. The method of claim 1, further comprising arranging a substantiallytransparent protective coating over the energy transmissive layer. 11.The method of claim 1, the energy transmissive layer being arranged topass 80% or more of light energy impinging on the energy transmissivelayer through the energy transmissive layer to activate the energyharvesting element.
 12. The method of claim 1, the energy harvestingelement being arranged on a surface of the one of the mobile device bodystructure or casing by being at least partially accommodated in a cavityin the surface of the one of the mobile device body structure or casing.